I've noticed that the mint mark on nickels are slightly off kilter it seems on a lot of years well into the 90's. But I have this 86 where the mint mark is more tilted, and also closer to the date than the other year coins I have.
The mintmark was hand-punched into the die until 1990, so it stands to reason that variations in position exist. Chris
If you would like to see examples of wildly varying mintmark placement, check out Kennedy half dollars of the 70's. Chris